lwresd.c

bind 9.3结合mysql数据库

	INSIST(VALID_LWRESD(*lwresdp));

	lwresd = *lwresdp;
	*lwresdp = NULL;

	LOCK(&lwresd->lock);
	INSIST(lwresd->refs > 0);
	lwresd->refs--;
	if (lwresd->refs == 0)
		done = ISC_TRUE;
	UNLOCK(&lwresd->lock);

	if (!done)
		return;

	dns_view_detach(&lwresd->view);
	if (lwresd->search != NULL)
		ns_lwsearchlist_detach(&lwresd->search);
	mctx = lwresd->mctx;
	lwresd->magic = 0;
	isc_mem_put(mctx, lwresd, sizeof(*lwresd));
	isc_mem_detach(&mctx);
}


/*
 * Handle listener objects
 */
void
ns_lwreslistener_attach(ns_lwreslistener_t *source,
			ns_lwreslistener_t **targetp)
{
	INSIST(VALID_LWRESLISTENER(source));
	INSIST(targetp != NULL && *targetp == NULL);

	LOCK(&source->lock);
	source->refs++;
	UNLOCK(&source->lock);

	*targetp = source;
}

void
ns_lwreslistener_detach(ns_lwreslistener_t **listenerp) {
	ns_lwreslistener_t *listener;
	isc_mem_t *mctx;
	isc_boolean_t done = ISC_FALSE;

	INSIST(listenerp != NULL && *listenerp != NULL);
	INSIST(VALID_LWRESLISTENER(*listenerp));

	listener = *listenerp;

	LOCK(&listener->lock);
	INSIST(listener->refs > 0);
	listener->refs--;
	if (listener->refs == 0)
		done = ISC_TRUE;
	UNLOCK(&listener->lock);

	if (!done)
		return;

	if (listener->manager != NULL)
		ns_lwdmanager_detach(&listener->manager);

	if (listener->sock != NULL)
		isc_socket_detach(&listener->sock);

	listener->magic = 0;
	mctx = listener->mctx;
	isc_mem_put(mctx, listener, sizeof(*listener));
	isc_mem_detach(&mctx);
	listenerp = NULL;
}

static isc_result_t
listener_create(isc_mem_t *mctx, ns_lwresd_t *lwresd,
		ns_lwreslistener_t **listenerp)
{
	ns_lwreslistener_t *listener;

	REQUIRE(listenerp != NULL && *listenerp == NULL);

	listener = isc_mem_get(mctx, sizeof(ns_lwreslistener_t));
	if (listener == NULL)
		return (ISC_R_NOMEMORY);
	RUNTIME_CHECK(isc_mutex_init(&listener->lock) == ISC_R_SUCCESS);

	listener->magic = LWRESLISTENER_MAGIC;
	listener->refs = 1;

	listener->sock = NULL;

	listener->manager = NULL;
	ns_lwdmanager_attach(lwresd, &listener->manager);

	listener->mctx = NULL;
	isc_mem_attach(mctx, &listener->mctx);

	ISC_LINK_INIT(listener, link);
	ISC_LIST_INIT(listener->cmgrs);

	*listenerp = listener;
	return (ISC_R_SUCCESS);
}

static isc_result_t
listener_bind(ns_lwreslistener_t *listener, isc_sockaddr_t *address) {
	isc_socket_t *sock = NULL;
	isc_result_t result = ISC_R_SUCCESS;
	int pf;

	pf = isc_sockaddr_pf(address);
	if ((pf == AF_INET && isc_net_probeipv4() != ISC_R_SUCCESS) ||
	    (pf == AF_INET6 && isc_net_probeipv6() != ISC_R_SUCCESS))
		return (ISC_R_FAMILYNOSUPPORT);

	listener->address = *address;

	if (isc_sockaddr_getport(&listener->address) == 0) {
		in_port_t port;
		port = lwresd_g_listenport;
		if (port == 0)
			port = LWRES_UDP_PORT;
		isc_sockaddr_setport(&listener->address, port);
	}

	sock = NULL;
	result = isc_socket_create(ns_g_socketmgr, pf,
				   isc_sockettype_udp, &sock);
	if (result != ISC_R_SUCCESS) {
		isc_log_write(ns_g_lctx, NS_LOGCATEGORY_GENERAL,
			      NS_LOGMODULE_LWRESD, ISC_LOG_WARNING,
			      "failed to create lwres socket: %s",
			      isc_result_totext(result));
		return (result);
	}

	result = isc_socket_bind(sock, &listener->address);
	if (result != ISC_R_SUCCESS) {
		char socktext[ISC_SOCKADDR_FORMATSIZE];
		isc_sockaddr_format(&listener->address, socktext,
				    sizeof(socktext));
		isc_socket_detach(&sock);
		isc_log_write(ns_g_lctx, NS_LOGCATEGORY_GENERAL,
			      NS_LOGMODULE_LWRESD, ISC_LOG_WARNING,
			      "failed to add lwres socket: %s: %s",
			      socktext, isc_result_totext(result));
		return (result);
	}
	listener->sock = sock;
	return (ISC_R_SUCCESS);
}

static void
listener_copysock(ns_lwreslistener_t *oldlistener,
		  ns_lwreslistener_t *newlistener)
{
	newlistener->address = oldlistener->address;
	isc_socket_attach(oldlistener->sock, &newlistener->sock);
}

static isc_result_t
listener_startclients(ns_lwreslistener_t *listener) {
	ns_lwdclientmgr_t *cm;
	unsigned int i;
	isc_result_t result;

	/*
	 * Create the client managers.
	 */
	result = ISC_R_SUCCESS;
	for (i = 0; i < NTASKS && result == ISC_R_SUCCESS; i++)
		result = ns_lwdclientmgr_create(listener, NRECVS,
						ns_g_taskmgr);

	/*
	 * Ensure that we have created at least one.
	 */
	if (ISC_LIST_EMPTY(listener->cmgrs))
		return (result);

	/*
	 * Walk the list of clients and start each one up.
	 */
	LOCK(&listener->lock);
	cm = ISC_LIST_HEAD(listener->cmgrs);
	while (cm != NULL) {
		result = ns_lwdclient_startrecv(cm);
		if (result != ISC_R_SUCCESS)
			isc_log_write(ns_g_lctx, NS_LOGCATEGORY_GENERAL,
				      NS_LOGMODULE_LWRESD, ISC_LOG_ERROR,
				      "could not start lwres "
				      "client handler: %s",
				      isc_result_totext(result));
		cm = ISC_LIST_NEXT(cm, link);
	}
	UNLOCK(&listener->lock);

	return (ISC_R_SUCCESS);
}

static void
listener_shutdown(ns_lwreslistener_t *listener) {
	ns_lwdclientmgr_t *cm;

	cm = ISC_LIST_HEAD(listener->cmgrs);
	while (cm != NULL) {
		isc_task_shutdown(cm->task);
		cm = ISC_LIST_NEXT(cm, link);
	}
}

static isc_result_t
find_listener(isc_sockaddr_t *address, ns_lwreslistener_t **listenerp) {
	ns_lwreslistener_t *listener;

	INSIST(listenerp != NULL && *listenerp == NULL);

	for (listener = ISC_LIST_HEAD(listeners);
	     listener != NULL;
	     listener = ISC_LIST_NEXT(listener, link))
	{
		if (!isc_sockaddr_equal(address, &listener->address))
			continue;
		*listenerp = listener;
		return (ISC_R_SUCCESS);
	}
	return (ISC_R_NOTFOUND);
}

void
ns_lwreslistener_unlinkcm(ns_lwreslistener_t *listener, ns_lwdclientmgr_t *cm)
{
	REQUIRE(VALID_LWRESLISTENER(listener));

	LOCK(&listener->lock);
	ISC_LIST_UNLINK(listener->cmgrs, cm, link);
	UNLOCK(&listener->lock);
}

void
ns_lwreslistener_linkcm(ns_lwreslistener_t *listener, ns_lwdclientmgr_t *cm) {
	REQUIRE(VALID_LWRESLISTENER(listener));

	/*
	 * This does no locking, since it's called early enough that locking
	 * isn't needed.
	 */
	ISC_LIST_APPEND(listener->cmgrs, cm, link);
}

static isc_result_t
configure_listener(isc_sockaddr_t *address, ns_lwresd_t *lwresd,
		   isc_mem_t *mctx, ns_lwreslistenerlist_t *newlisteners)
{
	ns_lwreslistener_t *listener, *oldlistener = NULL;
	char socktext[ISC_SOCKADDR_FORMATSIZE];
	isc_result_t result;

	(void)find_listener(address, &oldlistener);
	listener = NULL;
	result = listener_create(mctx, lwresd, &listener);
	if (result != ISC_R_SUCCESS) {
		isc_sockaddr_format(address, socktext, sizeof(socktext));
		isc_log_write(ns_g_lctx, ISC_LOGCATEGORY_GENERAL,
			      NS_LOGMODULE_LWRESD, ISC_LOG_WARNING,
			      "lwres failed to configure %s: %s",
			      socktext, isc_result_totext(result));
		return (result);
	}

	/*
	 * If there's already a listener, don't rebind the socket.
	 */
	if (oldlistener == NULL) {
		result = listener_bind(listener, address);
		if (result != ISC_R_SUCCESS) {
			ns_lwreslistener_detach(&listener);
			return (ISC_R_SUCCESS);
		}
	} else
		listener_copysock(oldlistener, listener);

	result = listener_startclients(listener);
	if (result != ISC_R_SUCCESS) {
		isc_sockaddr_format(address, socktext, sizeof(socktext));
		isc_log_write(ns_g_lctx, ISC_LOGCATEGORY_GENERAL,
			      NS_LOGMODULE_LWRESD, ISC_LOG_WARNING,
			      "lwres: failed to start %s: %s", socktext,
			      isc_result_totext(result));
		ns_lwreslistener_detach(&listener);
		return (ISC_R_SUCCESS);
	}

	if (oldlistener != NULL) {
		/*
		 * Remove the old listener from the old list and shut it down.
		 */
		ISC_LIST_UNLINK(listeners, oldlistener, link);
		listener_shutdown(oldlistener);
		ns_lwreslistener_detach(&oldlistener);
	} else {
		isc_sockaddr_format(address, socktext, sizeof(socktext));
		isc_log_write(ns_g_lctx, ISC_LOGCATEGORY_GENERAL,
			      NS_LOGMODULE_LWRESD, ISC_LOG_NOTICE,
			      "lwres listening on %s", socktext);
	}

	ISC_LIST_APPEND(*newlisteners, listener, link);
	return (result);
}

isc_result_t
ns_lwresd_configure(isc_mem_t *mctx, cfg_obj_t *config) {
	cfg_obj_t *lwreslist = NULL;
	cfg_obj_t *lwres = NULL;
	cfg_obj_t *listenerslist = NULL;
	cfg_listelt_t *element = NULL;
	ns_lwreslistener_t *listener;
	ns_lwreslistenerlist_t newlisteners;
	isc_result_t result;
	char socktext[ISC_SOCKADDR_FORMATSIZE];
	isc_sockaddr_t *addrs = NULL;
	ns_lwresd_t *lwresd = NULL;
	isc_uint32_t count = 0;

	REQUIRE(mctx != NULL);
	REQUIRE(config != NULL);

	RUNTIME_CHECK(isc_once_do(&once, initialize_mutex) == ISC_R_SUCCESS);

	ISC_LIST_INIT(newlisteners);

	result = cfg_map_get(config, "lwres", &lwreslist);
	if (result != ISC_R_SUCCESS)
		return (ISC_R_SUCCESS);

	LOCK(&listeners_lock);
	/*
	 * Run through the new lwres address list, noting sockets that
	 * are already being listened on and moving them to the new list.
	 *
	 * Identifying duplicates addr/port combinations is left to either
	 * the underlying config code, or to the bind attempt getting an
	 * address-in-use error.
	 */
	for (element = cfg_list_first(lwreslist);
	     element != NULL;
	     element = cfg_list_next(element))
	{
		in_port_t port;

		lwres = cfg_listelt_value(element);
		CHECK(ns_lwdmanager_create(mctx, lwres, &lwresd));

		port = lwresd_g_listenport;
		if (port == 0)
			port = LWRES_UDP_PORT;

		listenerslist = NULL;
		(void)cfg_map_get(lwres, "listen-on", &listenerslist);
		if (listenerslist == NULL) {
			struct in_addr localhost;
			isc_sockaddr_t address;

			localhost.s_addr = htonl(INADDR_LOOPBACK);
			isc_sockaddr_fromin(&address, &localhost, port);
			CHECK(configure_listener(&address, lwresd, mctx,
						 &newlisteners));
		} else {
			isc_uint32_t i;

			CHECK(ns_config_getiplist(config, listenerslist,
						  port, mctx, &addrs, &count));
			for (i = 0; i < count; i++)
				CHECK(configure_listener(&addrs[i], lwresd,
							 mctx, &newlisteners));
			ns_config_putiplist(mctx, &addrs, count);
		}
		ns_lwdmanager_detach(&lwresd);
	}

	/*
	 * Shutdown everything on the listeners list, and remove them from
	 * the list.  Then put all of the new listeners on it.
	 */

	while (!ISC_LIST_EMPTY(listeners)) {
		listener = ISC_LIST_HEAD(listeners);
		ISC_LIST_UNLINK(listeners, listener, link);

		isc_sockaddr_format(&listener->address,
				    socktext, sizeof(socktext));

		listener_shutdown(listener);
		ns_lwreslistener_detach(&listener);

		isc_log_write(ns_g_lctx, ISC_LOGCATEGORY_GENERAL,
			      NS_LOGMODULE_LWRESD, ISC_LOG_NOTICE,
			      "lwres no longer listening on %s", socktext);
	}

 cleanup:
	ISC_LIST_APPENDLIST(listeners, newlisteners, link);

	if (addrs != NULL)
		ns_config_putiplist(mctx, &addrs, count);

	if (lwresd != NULL)
		ns_lwdmanager_detach(&lwresd);

	UNLOCK(&listeners_lock);

	return (result);
}

void
ns_lwresd_shutdown(void) {
	ns_lwreslistener_t *listener;

	RUNTIME_CHECK(isc_once_do(&once, initialize_mutex) == ISC_R_SUCCESS);

	while (!ISC_LIST_EMPTY(listeners)) {
		listener = ISC_LIST_HEAD(listeners);
		ISC_LIST_UNLINK(listeners, listener, link);
		ns_lwreslistener_detach(&listener);
	}
}